SAN ANTONIO — It was a crime that could not be allowed to go unsolved--a federal judge assassinated on orders from a family so rich in drug money it tried to buy its own brand of justice.

Ten years ago last month, a single rifle bullet struck U.S. District Judge John Wood in the back outside his home, just days before he was to preside over the drug conspiracy trial of Jimmy Chagra.

Wood, known as "Maximum John" for the sentences he gave in drug cases, was the first federal judge to be killed this century.

'Attack on System'

"The slaying was a traumatic occasion for an awful lot of people," said Jamie Boyd, a former federal prosecutor who worked on the Wood case and is now a Bexar County prosecutor. "It was an attack on the system, not just a judge, and it was a crime that had to be solved."

Prosecutors suspected Jimmy Chagra, and the FBI began meticulously putting its case together.

By the time of the first indictments in April, 1982, the FBI had conducted more than 30,000 interviews, collected more than 500,000 pieces of information and spent nearly $5 million. Trials and appeals pushed the tab to more than $11 million.

In 1983, Chagra was acquitted of murder and conspiracy to commit murder. But he later pleaded guilty in the attempt on the life of another official and is serving a life term. Because he helped prosecutors with an unrelated case, Chagra has disappeared into the anonymity of the Federal Witness Protection Program, though he remains in prison somewhere.

2 Others in Prison

Chagra's wife and a man convicted of taking the Chagras' $250,000 to kill Wood also are in prison.

Joe Chagra--a now-disbarred lawyer who advised his brother to have Wood killed--was released on parole last year and is working as a paralegal in El Paso.

Jimmy Chagra was an El Paso rug salesman who turned to the lucrative marijuana smuggling trade in the 1960s. By the time of Wood's slaying, prosecutors say, his drug empire stretched from Florida to Las Vegas.

He was known as a high roller who reportedly once paid off a casino debt of more than $900,000 in cash, and lost a $580,000 golf match.

Prosecutors say his generosity attracted con men--among them Charles Harrelson, who had served time on a 1968 murder-for-hire conviction.

Called Coldblooded

Harrelson--father of "Cheers" TV star Woody Harrelson--said he went to Las Vegas to dupe Jimmy Chagra out of $250,000. Prosecutors say he was a coldblooded trigger man.

"Jimmy felt he was above the system and that's why he had no compulsion for buying Harrelson's murder of Judge Wood, because as he accumulated so much wealth he believed he was bigger than our entire judicial system," said John C. Lawn, administrator of the Drug Enforcement Administration. He was an FBI agent in San Antonio when Wood was killed.

With Joe Chagra's testimony--given in exchange for a plea bargain--a jury was able to convict Elizabeth Chagra and Harrelson and his wife.

Harrelson was convicted of murder and conspiracy and sentenced to two consecutive life terms, plus five years in prison for obstructing justice. He has steadfastly denied any involvement in the Wood killing.

His wife at the time, Jo Ann Starr Harrelson, was convicted of perjury and obstructing justice and is serving 25 years in prison. Prosecutors say she bought the murder weapon.

Mrs. Chagra was convicted of conspiracy, tax fraud and obstruction of justice and sentenced to 40 years in prison.

Joe Chagra refused to testify against his brother.

Later Pleads Guilty

But at the same time Jimmy Chagra was acquitted of murder in Wood's death, he was convicted of possession of marijuana and obstruction of justice. And he later pleaded guilty to masterminding a plot to kill an assistant U.S. attorney, who escaped a barrage of bullets just six months before and six blocks from where Wood was killed. He was sentenced to life for the attempt on the prosecutor.

Joe Chagra, who pleaded guilty to conspiracy in the judge's death, spent nearly six years in federal prison before being paroled in March, 1988.